<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title>Promise</title>
		
	</head>
	<body>
		
	</body>
	<script>
		runAsync1()
		.then(function(data){
		    console.log(data);
		    return runAsync2();
		})
		.then(function(data){
		    console.log(data);
		    return runAsync3();
		})
		.then(function(data){
		    console.log(data);
		});
		function runAsync1(){
		    var p = new Promise(function(resolve, reject){
		        //做一些异步操作
		        setTimeout(function(){
		            console.log('异步任务1执行完成');
		            resolve('随便什么数据1');
		        }, 1000);
		    });
		    return p;            
		}
		function runAsync2(){
		    var p = new Promise(function(resolve, reject){
		        //做一些异步操作
		        setTimeout(function(){
		            console.log('异步任务2执行完成');
		            resolve('随便什么数据2');
		        }, 2000);
		    });
		    return p;            
		}
		function runAsync3(){
		    var p = new Promise(function(resolve, reject){
		        //做一些异步操作
		        setTimeout(function(){
		            console.log('异步任务3执行完成');
		            resolve('随便什么数据3');
		        }, 2000);
		    });
		    return p;            
		}
	</script>
</html>
